There are various instances during which it is desirable to utilize an oil well blow out control valve on the upper end of a well production tubing. Various forms of blow out control valves heretofore have been provided such as those disclosed in U.S. Pat. Nos.: 3,040,763, 3,137,348, 3,207,221, 3,589,667 and 3,720,260.
However, some of these previously known forms of blow out control valves are quite complex in structure and are thus expensive to manufacture and use. Further, other previously known forms of control valves do not include structure capable of forming a high pressure fluid-tight seal between the control valve and the associated production tubing, while others do not include structure for admitting mud into the production tubing after the control valve has been mounted on the production tubing and closed.
Accordingly, a need exists for an improved mechanically simplified form of blow out control valve which will be inexpensive to manufacture and use and also capable of forming a high pressure fluid-type seal between the control valve and the associated production tubing.